The present invention relates to the use of derivatives of dihydroxybenzenesulfonic acids and their physiologically acceptable salts for the manufacture of medicaments intended for the normalization of the endothelial function, for the treatment of sexual dysfunction, of vascular complications of diabetes and of vascular disorders of endothelial origin.
Recent studies have demonstrated that calcium dobesilate, ethamsylate and persilate exert effects on the endothelium in the sense of facilitating endothelium-dependent vascular relaxation. This effect is observed both in normal animals and in those in which vascular aging has been produced experimentally by means of the administration of high doses of vitamin D2. This activity of calcium dobesilate, of ethamsylate and of persilate may be reflected in man by effects which are therapeutically useful. In particular, it has been demonstrated that the erection of the penis is modulated by nitric oxide produced in the endothelium (A. L. Burnett et al., Science, 1992, 257, 401-403; J. Kajfer et al., N. Engl. J. Med., 1992, 326, 90-94; Editorial, Lancet, 1992, 340, 882-883) and that, under circumstances where the endothelial function is detrimentally affected, as in hyperlipidemias (K. Kugiyama et al., Nature, 1990, 344, 160-162), correction of the detrimental change normalizes the erectile function, measured with accuracy during nocturnal sleep (J.-B. Kostis et al., J. Clin. Pharmacol., 1994, 34, 989-996; R. C. Rosen, xe2x80x9cThe Pharmacology of Sexual Function and Dysfunctionxe2x80x9d, edited by J. Bancroft, Elsevier Sc., 1995, cages 277-287). The normalization of the endothelial function obtained with calcium dobesilate, ethamsylate and persilate can represent an entirely novel therapeutic approach to the problem of impotence (I. Saenz de Tejada et al., N. Engl. J. Med., 1989, 320, 1025-1030), both in patients with vascular disorders with various causes (diabetes, arteriosclerosis, and the like) and in patients where only a functional disorder can be detected.
Furthermore, the normalizing effect on the endothelial function can also offer therapeutic opportunities in vascular spasm processes, in complications of diabetes (W. Durante et al., Br. J. Pharmacol., 1988, 94, 463-468) and in all disorders, including premature ejaculation (E. M. Hull et al., Neuropharmacology, 1994, 33, 1499-1504), where a deficit in the formation of nitric oxide for the vascular endothelium appears evident.
The compounds recommended in the context of the present invention correspond to the general formula I: 
in which:
R represents a hydrogen atom (H) or a sulfonic group (SO)3xe2x80x94)
B represents a calcium atom (Ca++) or a diethylamine group [H2N+(C2H5) 2]
n represents 1 or 2
m represents 1 or 2.